Tea is known to have many health benefits and much research has linked the consumption of both black and green teas with the prevention and combat of many forms of cancer. There are three main types of tea that are consumed, these being green tea, black tea and Oolong tea. The differences in manufacturing processes of these teas mean that they contain different types of the polyphenols responsible for teas antioxidant activities.

Black tea which undergoes a fermentation process in manufacture contains mainly flavonols such as theaflavin, whereas green tea is not fermented and contains unoxidised catechins such as EGCG. This section takes a look into the relationship between tea consumption and the risk of prostate cancer.

Drinking Tea and the Risk of Developing Prostate Cancer

Studies have shown that there is a lower incidence rate of prostate cancer in regular green tea drinkers in Japan and China. In animals, research has shown that green tea polyphenols such as catechin are able to inhibit both the metastasis and development of prostate cancer, when the mice are given the human equivalent of six cups of green tea per day to drink. Additionally cell cultures of human prostate cancer cells have shown that the main catechin found in green tea EGCG is able to inhibit the cell growth of the cancer cells, disrupt their cell cycle, and induce their apoptosis. Additionally the green tea antioxidant EGCG is able to lower the amount of expression of prostate specific antigens and reduce the aggressiveness of prostate cancer. Furthermore, black tea has also been demonstrated to inhibit prostate tumour growths.

Drinking More Green Tea Helps to Lower the Risk of Prostate Cancer

Case studies carried out in China have shown that there is a correlation between the amount of green tea drank and the risk of developing prostate cancer. It was found that increased duration and quantity of green tea drinking lowered the incidence levels of prostate cancer.

Taken together it can be seen that the regular drinking of significant amounts of green tea (six cups per day) is very likely to both lower the risk of developing prostate cancer and supply the body with catechins that can be used to inhibit the growth and limit the proliferation of the cancer cells.

References

Adhami et al (2007). Combined inhibitory effects of green tea polyphenols and selective cyclooxygenase-2 inhibitors on the growth of human prostate cancer cells both in vitro and in vivo. Clinical Cancer Research 13: 1611 to 1619.
Gupta et al. (2001) Inhibition of prostate carcinogenesis in TRAMP mice by oral infusion of green tea polyphenols. PNAS 98: 10350 to 10355.
Khan and Mukhtar (2007) Tea polyphenols for health promotion. Life Sciences 81: 519
Pezzato et al. (2004). Prostate carcinoma and green tea: PSA-triggered basement membrane degradation and MMP-2 activation are inhibited by (－)epigallocatechin-3-gallate. International Journal of Cancer 112: 787
Siddiqui et al. (2005). Inhibition of CWR22R{nu}1 tumor growth and PSA secretion in athymic nude mice by green and black teas. Carcinogenesis 27: 833.